textproduct: Albany

WHAT HAS CHANGED

SPC has introduced a slight risk for severe weather across far southern zones tomorrow afternoon, although several limiting factors remain in play that may prevent much severe weather from occurring.

KEY MESSAGES

1) A strong cold front will bring gusty winds, showers, and a few thunderstorms to the region for Friday. Continued gusty and unseasonably chilly conditions are expected Friday night into Saturday. A coating of snow is possible in the high terrain Friday night.

2) Dry weather with temperatures moderating to near seasonable levels Sunday into early next week.

DISCUSSION

KEY MESSAGE 1...As of 2:45 PM EDT...Sfc high pressure remains centered just northwest of the region. With large-scale subsidence and low-level dry advection, morning clouds have diminished with mainly clear skies across the region this afternoon. Afternoon highs will be mainly in the 50s to low 60s. With clear skies and relatively calm winds, temperatures will drop quickly after sunset, especially for northern/northeastern areas. However, increasing mid and high clouds overnight will cause temps to level out and eventually rise the second half of the night. Lows will mainly occur before midnight, and will be in the upper 30s to 40s.

Tonight, a strengthening sfc low will track into the Great Lakes, and eventually towards the St Lawrence Valley tomorrow. This will lift a warm front northwards late tonight into tomorrow morning. Fairly strong warm advection/isentropic lift and a band of mid-level FGEN at the leading edge of a strengthening LLJ will allow for widespread showers to break out across the region the second half of tonight into tomorrow morning. With some elevated instability across our area, isolated to scattered embedded non-severe thunderstorms are also expected with these showers. PWATs increase to 1.5-1.75", so some moderate to briefly heavier periods of rain may be possible, making for a wet Friday AM commute.

The LLJ strengthens to 50-60 kt early tomorrow morning, and while we will not mix deep enough for gusts that strong to make it down to the surface, winds gusts increase as the LLJ moves overhead. Maximum gusts look to be on the order of 30-40 mph, with a few isolated gusts to 45 mph possible along the west facing slopes of the Taconics/southern Greens and around the Capital District due to flow channeling. These winds could knock down a few large limbs or trees, but are not expected to be strong enough or widespread enough to warrant advisory issuance. By mid-morning, showers will be lingering for northern areas, but a break in shower activity is expected for areas from around the Capital District south and east. Temperatures will be several degrees above normal here, with some low 70s possible thanks to 850 mb temps of +14 to +16C. It will remain breezy in the warm sector, although the core of the LLJ moves off to our north and east before any breaks of sun/deeper mixing occur.

Then, tomorrow afternoon and evening, the system's cold front tracks through the region as the sfc low tracks off to our north and east. Strong CVA and the right entrance of a jet streak to our north will provide forcing for ascent, leading to a line of showers and perhaps a few low-topped thunderstorms tomorrow afternoon ahead of the cold front. SPC has expanded the marginal risk for severe slightly further north and introduced a slight risk for portions of southern Ulster/Dutchess/Litchfield counties, although confidence remains low whether we will see much (if any) severe weather in our CWA. Limiting factors include: SBCAPE looks quite limited, with only 100 to possibly 250 J/kg, and will be confined mainly to the southeastern Catskills and Mid Hudson Valley. Additionally, there is a weak low-level cap seen in forecast soundings that will lead to the presence of some SBCIN. While a few breaks of sun are possible, much of the area in question will likely see fairly extensive cloud cover tomorrow as well that will limit the amount of destabilization. Low-level convergence at the front does not look quite as impressive in our area as for areas further to the south, as we will see a more gradual wind shift to the W/SW and eventually W/NW. Finally, any convection does not look to arrive in our area until ~4 PM, at which point we will already be starting to lose daytime heating. Low and mid-level wind fields remain impressive, so this is not to say we won't have gusty winds with this line of showers/storms tomorrow. However, confidence in these stronger winds aloft being able to mix down to the sfc and reach severe levels remains quite low.

The front moves off to our east early Friday night, with a much cooler airmass infiltrating the region in its wake. Showers come to and end for most of the region early Friday night, but lingering upslope/lake enhanced showers changing to snow showers are expected in the ADKs, southern Greens, and northern Catskills. By the time rain comes to an end, most areas will see a half inch to an inch of rain, with some locally higher amounts possible north of I-90. Given quick storm motions and long duration of the rain, no hydro issues expected. A coating to half inch of snow will be possible for the ADKs. Winds also remain gusty of out the W/NW Friday night through Saturday with deeper mixing in the cold advection regime and a tight pressure gradient across the region. Due to the very progressive nature of this system, winds don't look quite as strong as they did a couple days ago. Gusts could reach 30 to possibly 40 mph and will likely remain below advisory criteria. Winds diminish fairly quickly Saturday night after sunset with high pressure building in at the sfc. Saturday will be the coolest day of the fall so far with highs only in the 30s (terrain) to 40s (valleys).

KEY MESSAGE 2...Saturday night looks quite chilly with lows mainly in the 20s to low 30s. While the growing season has ended region-wide, will still mention that frost will be possible. High pressure is expected to remain in control of our weather through at least the middle of next week with zonal flow to weak, transient ridging aloft. While SUnday remain below normal (highs in the 40s to 50s), temperatures through the first half of the week moderate to near normal with quiet, tranquil weather expected.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Through 00z Saturday...VFR conditions will prevail through at least 06z Friday as high pressure over eastern New England tracks east off the coast. Conditions will then deteriorate to MVFR as a warm front quickly approaches from the west bringing some showers. A few downpours may occur early to mid Friday morning, so will continue mention of PROB30 for possible IFR conditions. Mainly IFR conditions are expected through much of Friday, although KPOU may improve to MVFR by late afternoon. A line of downpours along a cold front is anticipated to move through sometime between 20z-24z Friday. Will mention PROB30 for IFR conditions associated with +SHRA at KALB/KGFL/KPSF, but due to some instability will mention +TSRA at KPOU. Will refine timing in subsequent TAF issuances.

Will continue to mention low level wind shear at all sites starting early Friday morning, as a southerly jet of 40-45 kt at 2000 ft AGL moves overhead with sustained surface winds generally less than 15 kt. The LLWS should dissipate Friday afternoon. Surface winds will initially be variable less than 5 kt, becoming south-southeat and gradually increasing to 8-15 kt late tonight, with gusts of 20-30 kt developing at KALB/KPSF.

Outlook...

Friday Night: Low Operational Impact. Breezy. NO SIG WX. Saturday: Low Operational Impact. Breezy. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.